Lubricating system



NOV. 10, 1936. A, c b ET AL 2,060,752

LUBRICAT ING SYSTEM Filed'Jan. 2, 1955 2 Sheets-Sheet 1 JNVENTOR. PHIL/P 19. (4 mwE/a men/UR 01/010472 BY 0 Y ATTORNEY. v

N 10, 1936. P. A. CELANDER mp 2.060.752

LUBRICATING SYSTEM- 2 Sheets-Sheet 2 Filed Jan. 2, 1935 ATTORNEY.

Patented Nov. 10, 1936 UNITED STATES PATENT OFFICE LUBRICATING SYSTEMporation of Illinois Application January 2, 1935,. Serial No. 14

Claims.

This invention relates to improvements in lubricating systems and moreparticularly to a system for automatically lubricating the pistons of acompressor.

5 It has been found that in the compressors employed in the compressiontype of refrigerating apparatus, which employ a splash system oflubrication, insuflicient lubrication is provided for the pistons of thecompressor, and it is an object of this invention to provide a meansactuated by the operation of the compressor to automatically lubricatethe pistons of the compressor.

While the embodiment of this invention is illustrated and described inconnection with a compressor employed in a closed system compressiontype of refrigerating apparatus, yet it may be applied as well to anytype of compressor in which there is a differential in pressure betweenthe high and low sides.

With these and other objects in view, reference is made to theaccompanying sheets of drawings which illustrate preferred embodimentsof this invention with the understanding that minor changes may be madewithout departing from the scope thereof.

In the drawings:

Figure 1 is a view in transverse central vertical section taken througha compressor employed in a closed system compression type refrigeratingmachine, with parts shown in elevation, illustrating a preferred form ofthis invention.

Figure 2 is a fragmentary enlarged detail view of the preferred form ofautomatic compression cylinder lubricating means, shown in Figure 1.

Figure 3 is a View in section taken on the line 33, Figure 2, looking inthe direction of the arrows but omitting the showing of the cap means.

Figure 4 is a View in section taken on the line 4-4, Figure 1, lookingin the direction of the 40 arrows.

Figure 5 is a fragmentary view in section taken at right angles toFigure 1, illustrating a modified form of this invention.

Figure 6 is a view similar to Figure 5, illustrating the third form ofthis invention.

Figure 7 is a fragmentary sectional view taken on the line 44, Figure 1,illustrating an additional means for lubricating the wrist pin bearingsof the connecting rods, with parts in elevation.

Figure 8 is a view in central vertical section through a piston showingsaid additional means for lubricating the wrist pin bearings.

In the form of this invention illustrated in Figure 1, the crank shaft lis mounted in suitable bearings, not shown, in the crank case 2 with oneend extending therethrough and provided with a pulley wheel 3 to bedriven by a belt from an electric motor, or other means, not shown. Acompression cylinder head 4 is preferably formed integral with the crankcase upon the upper side thereof and the bottom of the crank case isshown provided with a removable cap 5. The eccentrics or cranks 6 of theshaft I mount the usual connecting rods 1 of the pistons 8. The shaftbearings and the bearings of the connecting rods 1 upon the wrist pinsare lubricated upon the rotation of the shaft by a bath of lubricantcontained in the bottom of the crank case, as indicated upon thedrawings.

In this embodiment, the gaseous refrigerant is compressed by theoperation of the pistons and is expelled under compression through thetop 9 of the cylinder head to be delivered through a pipe II] to thehigh side of an evaporator or cooling unit, not shown. The low side ofthe evaporator or cooling unit is connected by a pipe II to the port I2opening into the crank case 2 considerably above the level of thelubricant, all of which is usual construction.

In order to provide sufiicient lubrication to the pistons reciprocatingwithin the compressor 4, a pump cylinder is mounted upon the bottom ofthe cap 5, preferably centrally located thereon, to extend upwardbetween the eccentrics or cranks 6 of the shaft I. As shown in Figures 1and 2, the pump cylinder comprises a cylindrical casing I3 receivingwithin its lower end a plug I4 preferably threaded through an apertureprovided therefor in the center of the cap 5. The portion of the plug I4entering the interior of the cap 5 is provided with a transverse port I5communicating with an axial port l6 which passes upward through the bodyof the plug. The upper side of the plug within the cylinder casing I3 isrecessed and mounts a valve plate I! adapted to reciprocate between thebottom of the recess and an abutment I8, preferably formed of a splitring engaged in a circumferential groove in the side walls of therecess. In one position the valve plate I! is adapted to seat over theaxial port I6. It is preferable to provide the periphery of the valveplate II with a plurality of circumferential cutaway portions I9, asshown in Figure 3, to allow passage of fluid thereabout when the plateI! is unseated. The upper end of the casing I3 is provided with aclosure 20 which axially mounts a tube 2I depending therefrom andterminated a short distance above the recessed end of the plug I4. Thepipe 2| communicates with an axial 55 recess 22 in the closure 20 whichmounts a ball check valve 23. The axial recess 22 is provided with aclosure 24 which axially mounts a pipe 25 communicating with the recess22. The pipe 25 is extended through the crank case, preferably through aconnection 26 provided at one side of the cap 5, which in turn isconnected by the pipe 21 to a similar connection 28 threaded into theside of the cylinder head 4 intermediate the respective cylindersthereof to communicate with ports 29 extending through the walls thereofwhich in turn open into the interior of the cylinders below the pistonrings of the pistons 8 in their lowermost position, and preferablyarranged to be aligned with circumferential grooves 29 upon the pistonswhen the pistons are at the end of their downward stroke.

When the compressor is first installed, the crank case is filled withlubricant to the proper level. The lubricant will enter through theports l5 and 16 to unseat the valve plate I! and enter within the casingI3 of the cylindrical pump cylinder until the pressure of the airentrapped therein above the level of the lubricant is equal to thepressure of the lubricant in the crank case above the level of thelubricant within said casing. Upon the initiation of operation of thecompressor, the pressure Within the crank case 2 is reduced and as theports 29 are alternately uncovered by the pistons, the expansion of theair within the casing l3 of the cylindrical pumping member will causethe valve plate I! to seat upon the axial port l6 and force thelubricant therein through the pipes 21, 25, and 21 to the ports 29 todeliver the lubricant to the grooves 29 of the cylinders 8. Incompressors employed for the purpose described, their operation isintermittent, and upon the cessation of operation the pressure withinthe crank case 2 will increase and thereby force the lubricant withinthe crank case 2 to enter the casing [3 of the lubricant pump to againcompress the air therein, so that as soon as the exterior pressure isreduced, lubricant will again be fed to the cylinders.

Figure 5 illustrates a modified form of this device in which a metaldisc 30 is mounted between the crank casing 2 and cap 5. The disc 36 isprovided with a central opening 3| communicating with a chamber 32provided upon the upper side thereof mounting a ball check 33 andcommunicating with the pipe 34 extending upwardly and about theeccentrics of the shaft l to enter into the web 35 between the cylindersin the cylinder head 4 to communicate with the transverse port 36opening into the respective cylinders. The bottom of the cap 5 may beprovided with a small central opening 31 which communicates with theinterior of a metallic bellows 38 mounted upon the interior of the cap 5concentric with the opening 31. The bellows 38 is closed at its upperend and is normally maintained in extended position by a spring 39mounted upon the interior thereof. The metal disc 36 is provided with aport 40 and a flap valve 4| upon the under side thereof.

When the interior pressure of the crank case 2 increases, it will forcelubricant through port 48 and past the valve 4| to compress the bellows3B, exhausting the air therein through the opening 31, so that as thepressure within the crank case 2 decreases, the flap valve will beclosed and the lubricant entrapped by the valve below the disc 30 willbe forced by the expansion of the springpressed bellows 38 through thechamber 32 and pipe 34 to lubricate the pistons, as hereinbeforedescribed.

Figure 6 illustrates another form of thisinvention which includes themounting of a metallic bellows 42 upon a cylindrical base 43 formed uponthe interior of the cap 5. The bellows is closed at its upper end and isnormally maintained in extended position by a spring 44. The cap 5 isprovided with a port 45 leading from the interior at one side of thebellows 42 and then extended upward to communicate with the interior ofthe bellows 42. This port is provided upon the interior of thecylindrical base within the bellows with a flap valve 46. The cap 5 isprovided with another port 41 passing through the cylindrical base andleading from the interior of the bellows to a chamber 48, which chamberis provided with a flapper valve 49 adapted to close said port 41. Thechamber 48 communicates with a pipe 49 passing through the lower end ofthe cap which is connected to the cylinder head 4 of the compressor inthe manner shown in Figure 1.

Upon an increase in pressure within the crank case 2 the lubricant willbe passed through the port 45 to the interior of the bellows 42 andcompress the air entrapped therein until the pressures within andwithout the bellows are equal so that as the pressure within the crankcase 2 decreases, the pressure of the air within the bellows will forcethe lubricant through the port 41, chamber 48, and pipe 49 to lubricatethe cylinders, as hereinbefore described, as the pressure within thecrank case decreases.

If desired, the wrist pins 50 of the pistons 8 may be provided with anaxial bore 5| adapted to open into the circumferential groove 29 uponthe piston 8. The bore 50 is provided with a central port 52 leading atright angles therefrom to the connecting rod bearing 53 about the wristpins 58. By this means, each time the groove 29 registers with the port29 during operation of the pistons, then a part of the lubricantdelivered from the crank case through the port 29 will enter the wristpin bore 5| and be delivered through the port 52 to the connecting rodbearing 53.

From the above description, it is readily seen that by the provision ofthe lubricant pump within the crank case that during operation of thecompressor, a simple and effective automatic lubricating means for thepistons and piston wrist pin bearings is actuated by the differential inthe pressure upon the lubricant resulting from the operation of thecompressor.

What we claim is:

l. A compressor for a closed system compression type refrigerationapparatus having a crank case containing a bath of lubricant, alubricant pump for automatically lubricating the compressor pistonsactuated by the decrease in pressure within the crank case resultingfrom the operation of the pistons, including a chamber closed at one endand a valved port at the other provided with a valve permittinglubricant to enter the chamber until the pressure of the air entrappedtherein equals the pressure within the crank case when the compressor isidle, and means for delivering lubricant from the chamber to the pistoncylinders upon a reduction of crank case pressure upon initiation ofoperation.

2. The structure of claim 1 wherein the said delivery means includes apipe leading from the lubricant contained within the pump chamberprovided with a check valve preventing the return of lubricant therefromto the pump chamber.

3. The structure of claim 1 wherein the lubricant pump chamber includesa vertical cylindrical casing supported upon the bottom of the crankcase having said valved port adjacent the bottom thereof and wherein thesaid delivery means includes a pipe entering the casing and extendingadjacent the bottom above the said valved port.

4. The structure of claim 1 wherein the said pump chamber includes acompressible metallic bellows mounted upon a base formed upon the crankcase provided with a valved port leading from the interior of thebellows to the interior of the crank case and with an additional portleading from the interior of the bellows to the said delivery means.

5. The structure of claim 1 wherein each piston is provided with acircumferential groove below the piston rings arranged to receive thelubricant delivered to the cylinder and wherein each wrist pin of eachpiston terminates within the circumference of the piston formingcircumferential pockets traversing each circumferential piston grooveand wherein each wrist pin is provided with a lubricating duct leadingfrom said circumferential pockets to the bearing of the connecting rodupon the wrist pin.

PHILIP A. CELANDER. ARTHUR C. HOLLATZ.

